Infantile spams without hypsarrhythmia: A study of 16 cases

In this study, we present the electroclinical features and evolution of patients with epileptic spasms (ES) in clusters without hypsarrhythmia and with or without focal or generalized paroxysmal discharges on the interictal EEG. We also discuss how to nosologically define these cases.MethodsBetween February 1, 1990, and December, 2009, sixteen patients met the electroclinical diagnostic criteria of ES in clusters without hypsarrhythmia.ResultsES were cryptogenic in thirteen patients and symptomatic in three. Age at onset of ES was between 4 months and 30 months, with a mean age of 9 months and a median age of 7 months. Seven patients had seizures before the onset of ES. Focal spikes were observed in seven patients, bilateral spikes and spikes and waves in five, multifocal spikes in two, and two patients had a normal EEG. The ictal EEG recording showed diffuse high-amplitude slow waves in ten patients, diffuse slow waves followed by voltage attenuation in four patients, and diffuse fast rhythms in two. ES were cured in five patients. Mean follow-up was 6 years. Neuropsychological development has been normal in the five latter patients. Eleven patients continue with seizures refractory to antiepileptic drugs after a mean follow-up of 10 years. Of these eleven patients, five have severe mental retardation, three have moderate mental retardation, and two have mild mental retardation. All of them show behavioral disturbances.ConclusionThe patients in this series may be considered to have a variant of West syndrome rather than an electroclinically distinct epileptic syndrome.